Embassy of requires a clear copy of the signer ID.
If the document was issued by a government agency, then the person who is requesting the certification must submit a copy of his/her ID.

The Embassy of Bangladesh wants to know for what purpose your company is requesting document legalization. On your company letterhead, please type a letter addressed to the Consular which states the reason you need the stamp from the embassy of Bangladesh. The embassy is rejecting any document that is not accompanied by this letter.